With recent advances in mobile technologies, mobile commerce is having an increasingly profound impact on our daily lives, and beginning to offer interesting and advantageous new services. In particular, the mobile payment (m-payment) system has emerged, enabling users to pay for goods and services using their mobile devices (especially mobile phones) wherever they go. Mobile payment is anticipated to enjoy a bright future. In this paper, we reviewed the relevant literature regarding mobile payment services, analyzed the impact of m-payment system characteristics and user-centric factors on m-payment usage across different types of mobile payment users, and suggested new directions for future research in this emerging field. To analyze the adoption behaviors of m-payment users, we proposed an m-payment research model which consists of two user-centric factors (personal innovativeness and m-payment knowledge) and four m-payment system characteristics (mobility, reachability, compatibility, and convenience). We evaluated the proposed model empirically, applying survey data collected from m-payment users regarding their perceptions on mobile payment. We also attempted to categorize m-payment users into early and late adopters and delineated the different factors for these two types of adoptors that affect their intention to use m-payment. The results indicate that the strong predictors of the intention to use m payment are perceived ease of use and perceived usefulness. All respondents reported that the compatibility of m-payment was not the primary reason in their decision to adopt it. Interestingly, our findings indicate that early adopters value ease of use, confidently relying on their own m-payment knowledge, whereas late adopters respond very positively to the usefulness of m-payment, most notably reachability and convenience of usage. Moreover, late adopters’ perceived ease of use is influenced by personal innovativeness, which can probably be best explained by the fact that innovative late adopters are tech-savvy and feel confident to use mpayment technologies for their needs. Our study will assist managers in implementing appropriate business models and service strategies for different m-payment user groups, allowing them to exert appropriate time, effort, and investment for mpayment system development. Our study also provides directions for future mobile payment-related studies.